Three ways to travel at (almost) the speed of light

One hundred years ago today, on May 29, 1919, measurements of a solar eclipse made it possible to verify Einstein 's theory of general relativity. Even before that, Einstein had developed the theory of special relativity, which revolutionized the way we understand light. To date, it provides insights into how particles move in space, a critical area of ​​research for protecting spacecraft and astronauts from radiation.

The theory of special relativity has shown that light particles, photons, pass through the vacuum at a constant speed of 670,616,629 miles at the hour, a speed extremely difficult to reach and impossible to surpass in this environment. Yet, everywhere in space, from black holes to our near-Earth environment, particles are actually accelerated at incredible speeds, some even reaching 99.9% of the speed of light.

One of NASA's work is to better understand how these particles are accelerated. The study of these ultrarapid or relativistic particles can ultimately help protect missions exploring the solar system, traveling to the moon, and can tell us more about our galactic quarter: a well-targeted particle of 39, a speed close to the speed of light, can also trigger many embedded electronic components could simultaneously have negative effects on the radiation on astronauts traveling in space when they go to the Moon or beyond.

Here are three ways in which acceleration occurs.

1. Electromagnetic fields

Most processes that accelerate particles at relativistic speeds work with electromagnetic fields – the same force that holds magnets on your refrigerator. The two components, electric and magnetic fields, look like two sides of the same coin, acting together to whip up particles at relativistic speeds throughout the universe.

In essence, electromagnetic fields accelerate charged particles as they feel a force in an electromagnetic field that pushes them in the same way that gravity pulls mass objects. Under the right conditions, electromagnetic fields can accelerate particles at a speed close to light.

On Earth, electric fields are often specifically operated on a smaller scale to accelerate particles in laboratories. Particle accelerators, such as Large Hadron Collider and Fermilab, use pulsed electromagnetic fields to accelerate charged particles up to 99.99999896% the speed of light. At these speeds, particles can be broken together to produce collisions with huge amounts of energy. This allows scientists to search for elementary particles and understand what the universe looked like in the very first fractions of a second after the Big Bang.

2. Magnetic explosions

Magnetic fields are omnipresent in space, surrounding the Earth and covering the solar system. They even guide charged particles moving through space, spiraling around fields.

When these magnetic fields meet, they can become entangled. When the tension between the crossed lines becomes too great, the lines break and realign explosively in a process called magnetic reconnection. The rapid change in the magnetic field of a region creates electric fields, which causes the elimination of all the corresponding charged particles at high speeds. Scientists suspect that magnetic reconnection is a means by which particles, such as the solar wind, which is the constant flux of charged particles emitted by the sun, are accelerated at relativistic speeds.

These fast particles also create a variety of side effects near planets. Magnetic reconnection occurs near us at points where the sun's magnetic field pushes against the Earth's magnetosphere, its protective magnetic environment. When magnetic reconnection occurs on the side of the Earth opposite to the sun, the particles can be projected into the upper atmosphere of the Earth where they cause auroras. Magnetic reconnection is also considered responsible for other planets like Jupiter and Saturn, but in a slightly different way.

NASA's multi-scale magnetospheric spacecraft have been designed and constructed to include all aspects of magnetic reconnection. With the help of four identical spacecraft, the mission flies over the Earth to capture magnetic reconnection in action. The results of the analyzed data can help scientists understand the acceleration of particles at relativistic speeds around the Earth and throughout the universe.

3. Wave-particle interactions

Particles can be accelerated by interactions with electromagnetic waves, called wave-particle interactions. When electromagnetic waves collide, their fields can compress. The charged particles that bounce between the waves can gain energy similar to that of a ball that bounces between two melt walls.

These types of interactions occur constantly in the near space of the Earth and are responsible for accelerating the particles up to speeds that can damage the electronic components of the spacecraft and the satellites in them. l & # 39; space. NASA's missions, such as the Van Allen probes, help scientists understand wave-particle interactions.

It is also believed that wave-particle interactions are responsible for the acceleration of some cosmic rays outside our solar system. After a supernova explosion, a dense and hot shell of compressed gas called an explosive wave is ejected from the stellar nucleus. Filled with magnetic fields and charged particles, the wave-particle interactions in these bubbles can emit high-energy cosmic rays at 99.6% of the speed of light. Wave-particle interactions may also be partially responsible for accelerating the solar wind and the cosmic rays of the sun.

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